package servlets.module;

import dbProcs.Getter;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.owasp.encoder.Encode;
import utils.CountdownHandler;
import utils.InvalidCountdownStateException;
import utils.ModuleBlock;
import utils.ShepherdLogManager;
import utils.Validate;

/**
 * Responsable for returning the directories of modules <br>
 * <br>
 * This file is part of the Security Shepherd Project.
 *
 * <p>The Security Shepherd project is free software: you can redistribute it and/or modify it under
 * the terms of the GNU General Public License as published by the Free Software Foundation, either
 * version 3 of the License, or (at your option) any later version.<br>
 *
 * <p>The Security Shepherd project is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
 * PURPOSE. See the GNU General Public License for more details.<br>
 *
 * <p>You should have received a copy of the GNU General Public License along with the Security
 * Shepherd project. If not, see <http://www.gnu.org/licenses/>.
 *
 * @author Mark Denihan
 */
public class GetModule extends HttpServlet {

  private static final long serialVersionUID = 1L;
  private static final Logger log = LogManager.getLogger(GetModule.class);

  /**
   * Initiated by an Ajax call defined in index.jsp, this method takes a module identifier and
   * returns the valid directory of where the module's View structure is stored.
   *
   * @param moduleId The identifier of the module to be returned
   */
  public void doPost(HttpServletRequest request, HttpServletResponse response)
      throws ServletException, IOException {
    // Setting IpAddress To Log and taking header for original IP if forwarded from
    // proxy
    ShepherdLogManager.setRequestIp(request.getRemoteAddr(), request.getHeader("X-Forwarded-For"));
    log.debug("&&& servlets.module.GetModule &&&");
    response.setContentType("text/plain; charset=UTF-8");
    request.setCharacterEncoding("UTF-8");
    PrintWriter out = response.getWriter();
    out.print(getServletInfo());
    HttpSession ses = request.getSession(true);
    if (Validate.validateSession(ses)) {
      ShepherdLogManager.setRequestIp(
          request.getRemoteAddr(),
          request.getHeader("X-Forwarded-For"),
          ses.getAttribute("userName").toString());
      log.debug("Current User: " + ses.getAttribute("userName").toString());
      Cookie tokenCookie = Validate.getToken(request.getCookies());
      Object tokenParmeter = request.getParameter("csrfToken");
      if (Validate.validateTokens(tokenCookie, tokenParmeter)) {
        boolean notNull = false;
        String storedResult = null;
        boolean isAdmin = false;
        boolean isRunning = false;

        try {
          isRunning = CountdownHandler.isRunning();
        } catch (InvalidCountdownStateException e) {
          String message = "Countdown is in an invalid state: " + e.toString();
          log.error(message);
          throw new RuntimeException(e);
        }

        if (Validate.validateAdminSession(ses, tokenCookie, tokenParmeter)) {
          ShepherdLogManager.setRequestIp(
              request.getRemoteAddr(),
              request.getHeader("X-Forwarded-For"),
              ses.getAttribute("userName").toString());
          log.debug("Current User: " + ses.getAttribute("userName").toString());
          if (Validate.validateTokens(tokenCookie, tokenParmeter)) {
            isAdmin = true;
          }
        }

        String ApplicationRoot = getServletContext().getRealPath("");

        log.debug("Getting Parameters");
        String moduleId = request.getParameter("moduleId");

        if (moduleId == null) {
          log.error("Null module ID provided, exiting");
          return;
        }

        log.debug("moduleId = " + moduleId);

        log.debug("Getting session parameters");
        String userId = (String) ses.getAttribute("userStamp");
        log.debug("userId = " + userId);

        // Validation
        notNull = (moduleId != null);
        if (notNull) {
          storedResult = Getter.getModuleResult(ApplicationRoot, moduleId);
        }
        boolean moduleOpen = false;
        if (notNull && storedResult != null) {
          moduleOpen = Getter.isModuleOpen(ApplicationRoot, moduleId);
        }
        if (notNull && storedResult != null && moduleOpen) {
          // Data is good, Add result: Now to check if there is a block in place
          if (!isRunning && !isAdmin) {
            // CTF isn't running and user isn't admin
            log.debug("CTF isn't running, access denied");
            out.write("../blockedMessage.jsp");

          } else if (ModuleBlock.blockerEnabled && ModuleBlock.blockerId.compareTo(moduleId) == 0) {
            log.debug("Blocker Detected; Returning Message");
            out.write("../blockedMessage.jsp");
          } else {
            String theHash =
                Encode.forHtmlAttribute(Getter.getModuleAddress(ApplicationRoot, moduleId, userId));
            out.write(theHash);
            log.debug("Returning: " + theHash);
          }
        } else {
          // Validation Error Responses
          if (!notNull) {
            log.error("Null values detected");
          } else if (storedResult == null) {
            log.error("Module not found");
          } else {
            log.fatal("Module Not Open");
          }
        }

      } else {
        log.debug("CSRF Tokens did not match");
      }
    } else {
      log.error("Invalid Session Detected");
      out.write("css/images/loggedOutSheep.jpg");
    }
    log.debug("&&& END GetModule &&&");
  }
}
